The long-term objectives of the present proposal are to obtain data from chemopreventive studies in the hamster that will be useful in identifying agents likely to have efficacy in preventing cancer of the respiratory tract in the human. One specific aim is to evaluate three agents administered as single compounds for their capacity to inhibit squamous cell carcinogenesis of the upper respiratory tract of the Syrian Golden hamster. The three agents and their routes of administration are: green tea extract powder administered in the drinking water, budesonide administered by aerosol and myo-inositol administered in the diet. A second specific aim is to evaluate the efficacy of administration of combinations of two agents on their capacity to inhibit squamous cell carcinogenesis of the upper respiratory tract of the Syrian Golden hamster. The combinations will be selected from the agents enumerated above and also aerosol difluoromethylornithine which previously has been shown to have an inhibitory effect in the hamster model. The use of agent combinations can be valuable in decreasing the dose of individual compounds and thus possibly reducing adverse effects. The sequence of studies of agent efficacy will be selected so as to coordinate their use in the Clinical Trials Section-Project 1. A third aim is to determine molecular changes during squamous cell carcinogenesis of the upper respiratory tract of the hamster and to compare these with squamous cell carcinogenesis of the respiratory tract in the human. The hamster model employed entails six intratracheal administrations of the carcinogen MNU. With this procedure approximately 90% of the animals receiving carcinogen but no protective agent develop infiltrating squamous cell carcinomas of the upper respiratory tract, inhibition of the occurrence of these cancers would indicate that the chemopreventive agent has considerable potency and is a potential compound to further evaluate for use in the human.